| 1. |
- Bernhardsson, Christian, et al.
(author)
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ZERO POINT ASSESSMENT OF THE RADIATION ENVIRONMENT – EXAMPLES OF A PROGRAM APPLIED IN SWEDEN (ESS) AND IN BELARUS (BELNPP)
- 2019
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In: MEDICAL PHYSICS IN THE BALTIC STATES : Proceedings of the 14th International Conference on Medical Physics - Proceedings of the 14th International Conference on Medical Physics. ; , s. 85-88
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Conference paper (peer-reviewed)abstract
- Before commissioning of a nuclear facility it is important to determine the baseline of the radiation environment. Such baseline or Zero Point assessments can only,and uniquely, be made before start of operation of the facility and will serve several purposes when the facility is in operation. Here we report on the planning and implementation of such a Zero Point program for achieving high reproducibility and effectiveness of the assessments around two nuclear installations.
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| 2. |
- Blomstrand, Malin, et al.
(author)
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Estimated clinical benefit of protecting neurogenesis in the developing brain during radiation therapy for pediatric medulloblastoma.
- 2012
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In: Neuro-Oncology. - : Oxford University Press (OUP). - 1523-5866 .- 1522-8517. ; 14:7, s. 882-889
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Journal article (peer-reviewed)abstract
- We sought to assess the feasibility and estimate the benefit of sparing the neurogenic niches when irradiating the brain of pediatric patients with medulloblastoma (MB) based on clinical outcome data. Pediatric MB survivors experience a high risk of neurocognitive adverse effects, often attributed to the whole-brain irradiation that is part of standard management. Neurogenesis is very sensitive to radiation, and limiting the radiation dose to the hippocampus and the subventricular zone (SVZ) may preserve neurocognitive function. Radiotherapy plans were created using 4 techniques: standard opposing fields, intensity-modulated radiotherapy (IMRT), intensity-modulated arc therapy (IMAT), and intensity-modulated proton therapy (IMPT). Mean dose to the hippocampus and SVZ (mean for both sites) could be limited to 88.3% (range, 83.6%-91.0%), 77.1% (range, 71.5%-81.3%), and 42.3% (range, 26.6%-51.2%) with IMAT, IMRT, and IMPT, respectively, while maintaining at least 95% of the prescribed dose in 95% of the whole-brain target volume. Estimated risks for developing memory impairment after a prescribed dose of 23.4 Gy were 47% (95% confidence interval [CI], 21%-69%), 44% (95% CI, 21%-65%), 41% (95% CI, 22%-60%), and 33% (95% CI, 23%-44%) with opposing fields, IMAT, IMRT, and IMPT, respectively. Neurogenic niche sparing during cranial irradiation of pediatric patients with MB is feasible and is estimated to lower the risks of long-term neurocognitive sequelae. Greatest sparing is achieved with intensity-modulated proton therapy, thus making this an attractive option to be tested in a prospective clinical trial.
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| 3. |
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| 4. |
- Brodin, N Patrik, et al.
(author)
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Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique.
- 2014
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In: Neuro-oncology. - : Oxford University Press (OUP). - 1523-5866 .- 1522-8517. ; 16:4, s. 594-602
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Journal article (peer-reviewed)abstract
- BackgroundWe investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy.MethodsWe included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. Treatment plans were generated using 3D conformal radiotherapy, hippocampal sparing intensity-modulated radiotherapy, and spot-scanned proton therapy, using 3 different treatment margins for the conformal tumor boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques.ResultsMean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment margins (P < .05). The largest risk reduction, however, was seen when applying hippocampal sparing proton therapy-the estimated risk of impaired task efficiency (95% confidence interval) was 92% (66%-98%), 81% (51%-95%), and 50% (30%-70%) for 3D conformal radiotherapy, intensity-modulated radiotherapy, and proton therapy, respectively, for the smallest boost margin and 98% (78%-100%), 90% (60%-98%), and 70% (39%-90%) if boosting the whole posterior fossa. Also, the distance between the closest point of the planning target volume and the center of the hippocampus can be used to predict mean hippocampal dose for a given treatment technique.ConclusionsWe estimate a considerable clinical benefit of hippocampal sparing radiotherapy. In choosing treatment margins, the tradeoff between margin size and risk of neurocognitive impairment quantified here should be considered.
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| 5. |
- Brodin, N. Patrik, et al.
(author)
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Modeling freedom from progression for standard-risk medulloblastoma : A mathematical tumor control model with multiple modes of failure
- 2013
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In: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016. ; 87:2, s. 422-429
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Journal article (peer-reviewed)abstract
- Purpose As pediatric medulloblastoma (MB) is a relatively rare disease, it is important to extract the maximum information from trials and cohort studies. Here, a framework was developed for modeling tumor control with multiple modes of failure and time-to-progression for standard-risk MB, using published pattern of failure data. Methods and Materials Outcome data for standard-risk MB published after 1990 with pattern of relapse information were used to fit a tumor control dose-response model addressing failures in both the high-dose boost volume and the elective craniospinal volume. Estimates of 5-year event-free survival from 2 large randomized MB trials were used to model the time-to-progression distribution. Uncertainty in freedom from progression (FFP) was estimated by Monte Carlo sampling over the statistical uncertainty in input data. Results The estimated 5-year FFP (95% confidence intervals [CI]) for craniospinal doses of 15, 18, 24, and 36 Gy while maintaining 54 Gy to the posterior fossa was 77% (95% CI, 70%-81%), 78% (95% CI, 73%-81%), 79% (95% CI, 76%-82%), and 80% (95% CI, 77%-84%) respectively. The uncertainty in FFP was considerably larger for craniospinal doses below 18 Gy, reflecting the lack of data in the lower dose range. Conclusions Estimates of tumor control and time-to-progression for standard-risk MB provides a data-driven setting for hypothesis generation or power calculations for prospective trials, taking the uncertainties into account. The presented methods can also be applied to incorporate further risk-stratification for example based on molecular biomarkers, when the necessary data become available.
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| 6. |
- Broström, Göran, et al.
(author)
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Social class and sex-specific adult mortality during 200 years in Sweden
- 2019
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Conference paper (peer-reviewed)abstract
- Recent regional studies on adult mortality and socio-economic status inSweden are merged and also completed with analyses from country-widecensuses in strategic time periods, with the purpose to find out whetherthe locally drawn conclusions about a changing social gradient in mortalitystill holds.The answer is firmly positive: While the upper classes have definiteadvantage in modern time (after, say, the 1960s), the reverse situationholds during the nineteenth and early twentieth century for men. Women, onthe other hand, seem to follow the expected pattern of a positive socialgradient through the last 200 years.
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| 9. |
- Danared, Håkan, et al.
(author)
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Preface
- 2017
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In: IPAC 2018 : Proceedings of the 8th International Particle Accelerator Conference - Proceedings of the 8th International Particle Accelerator Conference. - 9783954501823
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Journal article (other academic/artistic)
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| 10. |
- Eriksson, Anna, et al.
(author)
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Epigenetic aberrations in acute myeloid leukemia : Early key events during leukemogenesis
- 2015
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In: Experimental Hematology. - : Elsevier BV. - 0301-472X .- 1873-2399. ; 43:8, s. 609-624
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Journal article (peer-reviewed)abstract
- As a result of the introduction of new sequencing technologies, the molecular landscape of acute myeloid leukemia (AML) is rapidly evolving. From karyotyping, which detects only large genomic aberrations of metaphase chromosomes, we have moved into an era when sequencing of each base pair allows us to define the AML genome at highest resolution. This has revealed a new complex landscape of genetic aberrations where addition of mutations in epigenetic regulators has been one of the most important contributions to the understanding of the pathogenesis of AML. These findings, together with new insights into epigenetic mechanisms, have placed dysregulated epigenetic mechanisms at the forefront of AML development. Not only have several new mutations in genes directly involved in epigenetic regulatory mechanisms been discovered, but also previously well-known gene fusions have been found to exert aberrant effects through epigenetic mechanisms. In addition, mutations in epigenetic regulators such as DNMT3A, TET2, and ASXL1 have recently been found to be the earliest known events during AML evolution and to be present as preleukemic lesions before the onset of AML. In this article, we review epigenetic changes in AML also in relation to what is known about their mechanism of action and their prognostic role.
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